Use of these functions allows the user to specify
a set of default parameters for each Symbol
to be
loaded.
Different sources (e.g. yahoo, MySQL, csv),
can be specified for each Symbol of
interest. The sources must be valid
getSymbols
methods - see getSymbols
for details on which methods are available, as well as
how to add additional methods.
The argument list to setSymbolLookup
is
simply the unquoted name of the Symbol
matched
to the desired default source, or list of Symbol
specific parameters.
For example, to signify that the stock data for
Sun Microsystems (JAVA) should be downloaded from
Yahoo! Finance, one would call
setSymbolLookup(JAVA='yahoo')
or setSymbolLookup(JAVA=list(src='yahoo'))
It is also possible to specify additional,
possibly source specific, lookup details on
a per symbol basis. These include an alternate
naming convention (useful for sites like Yahoo! where
certain non-traded symbols are prepended with a caret,
or more correctly a curcumflex accent. In that case one would
specify setSymbolLookup(DJI=list(name="^DJI",src="yahoo"))
)
as well as passed parameters like dbname
and
password
for database sources. See the
specific getSymbols function related to the source
in question for more details of each implementation.
If a single named list is passed into the function without naming
the list as a parameter, the names of this list will be presumed
to be symbol names to be added to the current list of symbols.
All changes are made to the current list, and will
persist only until the end of the session. To always
use the same defaults it is necessary to call
setSymbolLookup
with the appropriate
parameters from a startup file (e.g.
.Rprofile) or to use saveSymbolLookup
and
loadSymbolLookup
to save and restore lookup
tables.
To unset a specific Symbol's defaults, simply assign
NULL
to the Symbol.